On Raspberry Pi platform GPIO controller also responsible for pins
multiplexing. Pi code predates proper FDT support in FreeBSD so a
lot of pinmux info is hardcoded. This patch:
- Implements pinctl methods in bcm2835_gpio
- Converts all devices with ad-hoc pinmux info to proper pin control
mechanisms and adds pinmux info in FreeBSD's custom dts files.
- Adds fdt_pinctrl option to RPI2 and RPI-B kernels
- Adds SPI pinmux config to FreeBSD's customization of GNU DTS.
Reviewed by: imp, manu
Differential Revision: https://reviews.freebsd.org/D14104
A comment in bcm_bsc_fill_tx_fifo() even lists sc_totlen > 0 as a
precondition for calling the routine. I apparently forgot to make the
code do what my comment said.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
common case where it's needed -- a write followed by a read to the same slave.
The i2c controller in this chip only performs complete transfers, it does
not provide control over start/repeat-start/stop operations on the bus.
Thus, we have gotten a full stop/start sequence rather than a repeat-start
when doing a typical i2c slave access of "write address, read data". Some
i2c slave devices require a repeat-start to work correctly.
These changes cause the controller to do a repeat-start by pre-staging the
read parameters in the controller registers immediate after the controller
has latched the values for the initial write operation, but before any
bytes are actually written. With the values pre-staged, when the write
portion of the transfer completes, the state machine in the silicon sees
a new start operation already staged and that causes it to perform a
repeat-start. The key to tricking the buggy hardware into doing this is
to avoid prefilling any output data in the transmit FIFO so that it is
possible to catch the silicon in the state where transmit values are
latched but the transmit isn't completed yet.
available, in i2c controller drivers that require interrupts for transfers.
This is the result of auditing all 22 existing drivers that attach iicbus.
These drivers were the only ones remaining that require interrupts and were
not using config_intrhook to defer attachment. That has led, over the
years, to various i2c slave device drivers needing to use config_intrhook
themselves rather than performing bus transactions in their probe() and
attach() methods, just in case they were attached too early.
FreeBSD uses upstream DTB for RPi3 build and compatibility string for
i2c device is different there. Add this new string to compatibility data.
Reported by: Karl Denninger
MFC after: 3 days
used for kernel devices it is used by i2c(8).
This fix the 'error: Device not configured' when i2c(8) tries to reset the
controller, as an example:
# i2c -r
Resetting I2C controller on /dev/iic0: error: Device not configured
For now use conservative settings for default i2c speeds.
MFC after: 1 week
EWOULDBLOCK.
Do not print any message at errors. The errors are properly sent to upper
layers which should be able to deal with it, including printing the errors
when they need to.
The error message was quite annoying while scanning the i2c bus.
MFC after: 1 week
This fix a race where the threads waiting for the bus would wake up early
and still see bus as busy.
While here, give a better description to wmesg for the two use cases we
have (bus and io waiting).
MFC after: 1 week
(7-bit device address << 1), always leaving the room for the read/write bit.
This commit convert ti_i2c and revert r259127 on bcm2835_bsc to make them
compatible with 8-bit addresses. Previous to this commit an i2c device
would have different addresses depending on the controller it was attached
to (by example, when compared to any iicbb(4) based i2c controller), which
was a pretty annoying behavior.
Also, update the PMIC i2c address on beaglebone* DTS files to match the new
address scheme.
Now the userland utilities need to do the correct slave address shifting
(but it is going to work with any i2c controller on the system).
Discussed with: ian
MFC after: 2 weeks
to check the status property in their probe routines.
Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.
Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.
rely only on checking the device unit to indentify the BSC unit we are
attaching to. Make use of the device base address to identify our BSC unit.
Approved by: adrian (mentor)
